This proposal describes the continuation and expansion of our program funded under CA 47179. We maintain our original overall objectives of implementing a comprehensive multi-disciplinary program designed to address issues related to improved treatment of and understanding of the biology of soft tissue sarcomas (STS). A major resource of this program is the patient population: over the past 9 years, 1802 adult patients with STS have been admitted to MSKCC. We maintain a comprehensive prospective database on this population. In this revised proposal, the clinical studies (Project 0004) continue the multimodality approaches (chemotherapy, immunotherapy, and radiation therapy) to the diagnosis and treatment of selected groups of patients with STS. The monoclonal antibody studies represent a major expansion of our focus and are on the strong institutional commitment and program in the development of new biologicals for the treatment of cancer. Our initial studies of radiolabelled antibodies are a first step in the development of an expanded immunotherapy program. Both the chemotherapy and immunological approaches are tightly linked to the laboratory efforts and accomplishments in immunopathology (Project 0005) and drug resistance (Project 0003). The immunopathology project (Project 0005) will continue the immunophenotypic analysis of sarcomas with a focus on the study of (i) differentiation of myogenic tumors (ii) multistage carcinogenesis and tumor progression in sarcomas. Hypotheses generated in Project 0003 will be tested in some of the clinical trials in Project 1. The research projects are supported by 4 cores: Administrative, Clinical, Pathology and Biostatistical. Thus, the disciplines of surgery, medical and radiation oncology, pathology, immunology and biostatistics have been marshalled to study the biology and clinical care of STS.